Packet Scheduling in Wireless LANs — A Framework for a Noncooperative Paradigm

Abstract

Abstract:Contention-based packet scheduling policies incorporated into MAC protocols in wireless networks attempt to schedule one packet transmission per protocol cycle and are optimised to reduce the scheduling penalty while distributing the bandwidth fairly among the network stations. The paper points out the possibility of there being some noncooperative stations that, instead of adhering to a common-goal optimum policy, try to maximise their individual service rates to the detriment of the cooperative stations. A framework for noncooperative scheduling policies is postulated with analogies drawn from the auction paradigm; desirable features include verifiability at various levels, fairness and low performance cost. Upon discussing possible noncooperative station behaviour, four single-cyc1e noncooperative scheduling policies are proposed as modifications of the well-known EY-NPMA and Random Token policies. Results of a preliminary simulation study are presented to demonstrate that these modifications do prevent or at least discourage noncooperative stations from stealing bandwidth from cooperative ones.

Application of a hash function to discourage MAC-layer misbehaviour in wireless LANs

“…Following the approach in [9,10], we wish to develop an RT-type MAC protocol for which no rational selection strategy will perform substantially better than Randomiser. The following framework for MAC-layer misbehaviour is assumed:…”

“…In any instance of contention the winner is the station whose deferment is extreme among the contending stations; this condition is equivalent of capturing a unique token that visits the stations in random order rather than sequentially. By manipulating the probability distribution of transmission deferment a station can easily outperform stations that apply a standardprescribed probability distribution [9,10]. The purpose of this paper is to propose a new protocol called RT-hash in order to prevent MAC-layer misbehaviour.…”